1. Field
This disclosure generally relates to robotic systems, and particularly to robotic systems that employ image based machine vision for guidance.
2. Description of the Related Art
Robotic systems are used in a variety of settings and environments. Robotic systems typically include one or more robots having one or more robotic members that are movable to interact with one or more workpieces. For example, the robotic member may include a number of articulated joints as well as a claw, grasper, or other implement to physically engage or otherwise interact with or operate on a workpiece. For instance, a robotic member may include a welding head or implement operable to weld the workpiece. The robotic system also typically includes a robot controller comprising a robotic motion controller that selectively controls the movement and/or operation of the robotic member, for example controlling the position and/or orientation (i.e., pose). The robot motion controller may be preprogrammed to cause the robotic member to repeat a series of movements or steps to selectively move the robotic member through a series of poses.
Some robotic systems employ machine vision to locate the robotic member relative to other structures and/or to determine a position and/or orientation or pose of a workpiece. Such robotic systems typically employ one or more image sensors, for example cameras, and a machine vision controller coupled to receive image information from the image sensors and configured to process the received image information. The image sensors may take a variety of forms, for example CCD arrays or CMOS sensors. Such image sensors may be fixed, or may be movable, for instance coupled to the robotic member and movable therewith. Robotic systems may also employ other controllers for performing other tasks. In such systems, the robot motion controller functions as the central control structure through which all information passes.
Robotic systems may be employed in a variety of activities, for example the picking parts or other objects. While in some environments the parts or other objects are arranged in an orderly fashion, often the parts or objects are not arranged or are randomly collected, for example in a bin or other container or on a surface. Robotic operations in such environments are commonly referred to as “bin picking” even though there may not be an actual bin. In such situations, access by the robot to particular parts may be blocked by other parts or objects, or clusters of parts or objects may occur, for example in wells or corners. Such may prevent effective picking of the parts or objects, or may significantly slow down the bin picking operation. Effective and efficient robotic operations such as bin picking become increasingly important as manufacturing and packaging moves to increasingly higher levels of automation. Hence improvements to robotic operations are commercially desirable.